JP2009241555A - Protective layer transfer sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a protective layer transfer sheet excellent in performance enabling to maintain the light resistance of a thermal transfer image for a long term and to provide a printing article which enhances the light resistance by using this protective layer transfer sheet. <P>SOLUTION: In the protective layer transfer sheet which has a base material film and a heat transferable resin layer and which transfers the heat transferable resin layer into the image printed on an article to be transferred by thermal transfer; the heat transferable resin layer contains a copolymer in which a triazine compound having a reactive functional group is reacted and bonded. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a protective layer transfer sheet for use in a printed material on which an image is formed, and particularly relates to a protective layer transfer sheet that can improve the light resistance of yellow and magenta colors of the printed material over a long period of time.

In recent years, a thermal transfer method has been widely used as a simple printing method. In the thermal transfer method, a thermal transfer sheet provided with a color material layer on one surface of a base sheet and a thermal transfer image receiving sheet provided with an image receiving layer are overlapped, and the back side of the thermal transfer sheet is heated by heating means such as a thermal head. This is a method of forming an image on a thermal transfer image receiving sheet by heating it in an image form and selectively transferring the color material contained in the color material layer to the thermal transfer image receiving sheet.

Thermal transfer methods are classified into a melt transfer method and a sublimation transfer method. The melt transfer method uses a thermal transfer sheet in which a thermal melt ink layer in which a color material such as a pigment is dispersed in a binder such as a hot melt wax or resin is supported on a base sheet such as a PET film, and a thermal head or the like. In this image forming method, energy corresponding to image information is applied to a heating means, and a color material is transferred together with a binder onto a thermal transfer image receiving sheet such as paper or a plastic sheet. An image obtained by the melt transfer method has a high density and excellent sharpness, and is suitable for recording binary images such as characters.

On the other hand, the sublimation transfer method uses a thermal transfer sheet in which a dye layer, in which a dye that transfers heat mainly by sublimation is dissolved or dispersed in a resin binder, is supported on a base sheet such as a PET film, and is used to heat a thermal head or the like. This is an image forming method in which energy corresponding to image information is applied to a means, and only a dye is transferred and transferred onto a thermal transfer image receiving sheet in which a dye receiving layer is provided on a base sheet such as paper or plastic as necessary. In the sublimation transfer method, the amount of dye transfer can be controlled in accordance with the amount of energy applied, so that it is possible to form a gradation image in which the image density is controlled for each dot of the thermal head. Further, since the color material to be used is a dye, the formed image is transparent, and the reproducibility of intermediate colors when dyes of different colors are superimposed is excellent. Therefore, when using thermal transfer sheets of different colors such as yellow, magenta, cyan, black, etc., and transferring each color dye on the thermal transfer image receiving sheet, high-quality photographic tone full-color images with excellent reproducibility of intermediate colors can be obtained. Formation is possible.

By the way, in recent years, printers used in the thermal transfer system have been designed to increase the printing speed. When such a high-speed printer is used, it is necessary to select a dye to be used for the color material layer of the thermal transfer sheet in order to match the color of the obtained printed matter. In addition to the color purity required so far, for the purpose of increasing the density, color materials (dyes, etc.) having a high spectral extinction coefficient, a wide half-value width, and poor light resistance have come to be used. ing. For this reason, even if it is a dye with inferior light resistance, it exists in the condition which must be used for the color adjustment of a printed matter, and there existed a fault that the light resistance of the image obtained was inferior.

For such a defect, for example, Patent Document 1 discloses forming a protective layer to which an ultraviolet absorber or an antioxidant is added on a printed image. However, although the light resistance of the printed image is improved to some extent by forming such a protective layer, in the method of simply adding the ultraviolet absorber to the protective layer constituting resin, the ultraviolet absorber is heated by heat. There is a problem that the effect of the ultraviolet absorber decreases with time due to vaporization / divergence or decomposition.
On the other hand, for example, Patent Document 2 discloses that a reactive ultraviolet absorber is reactively bonded to the dye-receiving layer resin of the thermal transfer image-receiving sheet.
However, since the dye that forms an image by being transferred by heat by the sublimation transfer method is present relatively near the surface of the receiving layer resin, it is not effective to impart ultraviolet absorbing ability to the entire receiving layer resin. Further, when the amount of the ultraviolet absorber is increased, the original performance of the receiving layer resin is impaired, and other performances such as blurring of the image are impaired.
Japanese Patent No. 2925699 JP-A-5-221974

An object of the present invention is to provide a protective layer transfer sheet excellent in performance capable of maintaining the light resistance of a thermal transfer image for a long period of time, and a printed matter having improved light resistance using the same.

The present invention is a protective layer transfer sheet having a base film and a thermal transfer resin layer, and transferring the thermal transfer resin layer by thermal transfer onto an image printed on a transfer object, the thermal transfer resin The layer is a protective layer transfer sheet characterized by containing a copolymer obtained by reactively bonding a triazine compound having a reactive functional group.
The triazine-based compound having the reactive functional group preferably has a structure represented by the following general formula (1).

In General Formula (1), R ¹ represents an alkylene group having 1 to 6 carbon atoms, R ² represents a hydrogen atom or a methyl group, and R ³ represents an alkyl group or alkoxy group having 1 to 6 carbon atoms, or Represents a hydrogen atom.

In addition, the protective layer transfer sheet of the present invention further includes a dye layer of each color of yellow (Y), magenta (M), cyan (C) and / or black (Bk), or yellow (Y), magenta (M ), Cyan (C) and / or black (Bk) heat-meltable ink layers are preferably formed in the surface order on the base film.
Further, the present invention is a printed matter characterized in that the thermal transfer resin layer of the protective layer transfer sheet of the present invention is laminated on at least a part of a printing screen having an image colored with at least a dye.
Hereinafter, the present invention will be described in detail.

As a result of intensive investigations on a protective layer transfer sheet having a base film and a heat transferable resin layer and transferring the heat transferable resin layer by thermal transfer onto an image printed on a transfer target, It has been found that the ultraviolet absorption effect can be continuously maintained over a long period of time by including a copolymer in which the above-mentioned thermal transferable resin layer contains a triazine compound having a specific reactive functional group. It came to complete.

1, 2, 3 and 4 are cross-sectional views schematically showing an example of the protective layer transfer sheet of the present invention.
A protective layer transfer sheet 10 of the present invention shown in FIG. 1 has a configuration in which a thermal transfer resin layer 12 is provided as a single layer on one surface of a base film 11.
The protective layer transfer sheet 20 of the present invention shown in FIG. 2 is provided with a thermal transfer resin layer 22 on one surface of a base sheet 21, and the thermal transfer resin layer 22 is sequentially from the base sheet 21 side. The transparent resin layer 23 and the heat-adhesive resin layer 24 are laminated in two layers. In the protective layer transfer sheet 20 of the present invention having such a configuration, the copolymer obtained by reactively bonding a triazine compound having a reactive functional group, which will be described later, is a transparent resin layer 23 and / or a thermoadhesive resin layer 24. It is contained in.
The protective layer transfer sheet 30 of the present invention shown in FIG. 3 is provided with a thermal transfer resin layer 32 on one surface of a base film 31, and the thermal transfer resin layer 32 is sequentially from the base film 31 side. The transparent resin layer 33, the ultraviolet blocking layer 35, and the thermal adhesive resin layer 34 are laminated in three layers. In the protective layer transfer sheet 30 of the present invention having such a configuration, a copolymer obtained by reactively binding a triazine compound having a reactive functional group, which will be described later, is usually contained in the ultraviolet blocking layer 35 but is transparent. May also be included in the adhesive resin layer 33 and / or the thermal adhesive resin layer 34.
A protective layer transfer sheet 40 of the present invention shown in FIG. 4 has a release layer 46 on one surface of a base film 41, and a thermal transfer resin layer 42 is provided on the release layer 46. The thermal transfer resin layer 42 has a configuration in which a transparent resin layer 43, an ultraviolet blocking layer 45, and a thermal adhesive resin layer 44 are laminated in this order from the release layer 46 side. Furthermore, a back layer 47 that imparts heat resistance and slip properties is provided on the other surface of the base film 41. In the protective layer transfer sheet 40 of the present invention having such a configuration, a copolymer obtained by reactively bonding a triazine compound having a reactive functional group, which will be described later, is usually contained in the ultraviolet blocking layer 45 but is transparent. May also be included in the adhesive resin layer 43 and / or the thermal adhesive resin layer 44.
The back layer 47 has a function of preventing adhesion when thermally transferring with a thermal head of a printer. In the case of the configuration of FIGS. 1 to 3, although not illustrated, it can be provided as necessary. Moreover, it is unnecessary when the heat resistance and slipping property of the base film are good. In addition, the release layer 46 reduces the adhesiveness between the transparent resin layer 43 and the base film 41 when the peelability between the base film 41 and the transparent resin layer 43 is not appropriate. This layer is provided to facilitate the peeling of the layer 43, and this layer is not shown in the case of the configuration shown in FIGS. Of course, when the peelability between the base film 41 and the transparent resin layer 43 is good, the release layer 46 is unnecessary. When the release layer 46 is provided, the thermal transfer resin layer 42 including the transparent resin layer 43 is peeled off from the release layer 46 by transfer, and the release layer 46 itself remains on the base film 41 side. Constitute.
Below, the constituent material and manufacturing method of the protective layer transfer sheet of this invention and the printed matter obtained by transferring this are demonstrated.

(Base film)
The protective layer transfer sheet of the present invention has a base film.
It does not specifically limit as said base film, The thing similar to the conventionally well-known base film currently used for the protective layer transfer sheet can be used.
Specific examples of preferable substrate films include, for example, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyphenylene sulfide, polyether ketone, or polyether sulfone, which have high heat resistance, such as polypropylene, polycarbonate, cellulose acetate, and polyethylene. Examples thereof include stretched or unstretched films of plastics such as derivatives, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, polymethylpentene, and ionomer.
Moreover, the composite film which laminated | stacked 2 or more types of these materials can also be used.

The thickness of the base film can be appropriately selected depending on the material so that the strength, heat resistance and the like are appropriate, but usually a thickness of about 3 to 100 μm is preferably used.

Moreover, you may have the back layer provided by the conventional method as needed in the surface on the opposite side to the heat transferable resin layer side of a base film.

The protective layer transfer sheet of the present invention is usually stored in a wound state. That is, it is stored in a state where the surface of the base film opposite to the thermal transfer resin layer is in contact with the thermal transfer resin layer. Therefore, the protective layer transfer sheet of the present invention has a surface opposite to the thermal transfer resin layer of the base film so that the base film and the thermal transfer resin layer do not adhere at least during storage. It is preferable that the surface of the heat transferable resin layer is provided with releasability by a release treatment, a release film sticking or the like.

(Thermal transfer resin layer)
The protective layer transfer sheet of the present invention has a thermal transfer resin layer.
The thermal transfer resin layer is formed on the base film, and is a layer transferred onto an image printed on a transfer medium by thermal transfer as will be described later.
In the protective layer transfer sheet of the present invention, the thermal transfer resin layer contains a copolymer in which a triazine compound having a reactive functional group is reactively bonded.

The triazine-based compound having a reactive functional group is a compound having a structure in which a reactive functional group is introduced into a triazine compound having ultraviolet absorbing performance, and having reactivity and ultraviolet absorbing performance.
Since the protective layer transfer sheet of the present invention contains a copolymer in which a triazine compound having such a reactive functional group (hereinafter also referred to as a reactive ultraviolet absorber) is reactively bonded to the thermal transfer resin layer, It has the effect of being excellent in the ability to maintain the light resistance of the thermal transfer image for a long period of time. This is because the triazine compound having the ultraviolet absorbing performance is contained in the heat transferable resin layer as a copolymer reactively bonded with a resin component described later, and therefore, the heat of the triazine compound having the reactive functional group. This is considered to be because there is little vaporization, divergence, decomposition, etc., and the ultraviolet absorption effect can be maintained for a long time. In particular, when the thermal transfer resin layer of the protective layer transfer sheet of the present invention is transferred and laminated on the print screen of a printed matter having a dye image such as by sublimation transfer, it is resistant to friction, scratch, and chemical. In particular, light resistance is improved as well as storage resistance.
Heretofore, as a thermal transfer image receiving sheet, a sheet containing a resin obtained by copolymerizing benzophenone or benzotriazole in a dye receiving layer is known. FIG. 7 shows the absorbance of the resin copolymerized with benzophenone, the absorbance of the resin copolymerized with benzotriazole, and the absorbance of the copolymer in which the triazine compound having the reactive functional group in the present invention is bonded. The graph of is shown. In FIG. 7, the absorbance of the resin copolymerized with benzophenone is simply expressed as “benzophenone”, the absorbance of the resin copolymerized with benzotriazole is simply expressed as “benzotriazole”, and the triazine having the reactive functional group. A copolymer obtained by reaction bonding of a system compound was denoted as “triazine”.
As shown in FIG. 7, the copolymer in which the triazine-based compound having a reactive functional group in the present invention is reactively bonded has a marked difference in absorbance compared to a conventional resin obtained by copolymerizing benzophenone and benzotriazole. This also shows that the light resistance is improved by the protective layer transfer sheet of the present invention.

In the triazine compound (reactive ultraviolet absorber) having the reactive functional group, examples of the reactive functional group include a functional group having an addition polymerizable double bond such as a vinyl group, an acryloyl group or a methacryloyl group, or , Alcoholic hydroxyl group, amino group, carboxyl group, epoxy group, isocyanate group and the like.
As the triazine compound having such a reactive functional group, a triazine compound represented by the following general formula (1) is preferably used. The protective layer transfer sheet of the present invention has a long-lasting light resistance, particularly in yellow and magenta colors, by including in the thermal transferable resin layer a copolymer obtained by reactively binding such a triazine compound having a reactive functional group. It will be excellent over time. Therefore, according to the protective layer transfer sheet of the present invention, even yellow and magenta dyes that are inferior in light resistance can be selectively used as the color material of the thermal transfer sheet, which is sufficient for speeding up the thermal transfer type printer. In addition to being able to cope with it, the resulting image has excellent light resistance.

In General Formula (1), R ¹ represents an alkylene group having 1 to 6 carbon atoms, R ² represents a hydrogen atom or a methyl group, and R ³ represents an alkyl group or alkoxy group having 1 to 6 carbon atoms, or Represents a hydrogen atom.

Specific examples of the triazine compound represented by the general formula (1) include 2,4-diphenyl-6- [2-hydroxy-4- (2-acryloyloxyethoxy)]-s-triazine. 2,4-bis (2-methylphenyl) -6- [2-hydroxy-4- (2-acryloyloxyethoxy)]-s-triazine, 2,4-bis (2-ethylphenyl) -6- [ 2-hydroxy-4- (2-acryloyloxyethoxy)]-s-triazine, 2,4-bis (2-ethoxyphenyl) -6- [2-hydroxy-4--2-acryloyloxyethoxy] -s-triazine 2,4-diphenyl-6- [2-hydroxy-4- (2-methacryloyloxyethoxy) -s-triazine, 2,4-bis (2-methylphenyl) -6- [2- Droxy-4- (2-methacryloyloxyethoxy) -s-triazine, 2,4-bis (2-methoxyphenyl) -6- [2-hydroxy-4- (2-methacryloyloxyethoxy) -s-triazine, 2 , 4-bis (2-ethylphenyl) -6- [2-hydroxy-4- (2-methacryloyloxyethoxy) -s-triazine, 2,4-bis (2-ethoxyphenyl) -6- [2-hydroxy -4- (2-methacryloyloxyethoxy) -s-triazine, 2,4-bis (2,4-dimethoxyphenyl) -6- [2-hydroxy-4- (2-acryloyloxyethoxy) -s-triazine, 2,4-bis (2,4-dimethylphenyl) -6- [2-hydroxy-4- (2-acryloyloxyethoxy) -s-triazine, 2 4-bis (2,4-diethoxyphenyl) -6- [2-hydroxy-4- (2-acryloyloxyethoxy) -s-triazine, 2,4-bis (2,4-diethylphenyl) -6 [2-hydroxy-4- (2-acryloyloxyethoxy) -s-triazine and the like.

In addition, as a method for obtaining a copolymer in which the reactive ultraviolet absorber is reactively bonded, various methods can be used. For example, conventionally known resin components such as monomers, oligomers or reactive polymers can be used. The method of radical-polymerizing the said reactive ultraviolet absorber is mentioned.
As the reactive ultraviolet absorber in this case, it is preferable to use a reactive ultraviolet absorber having a structure such as the general formula (1).
In addition, when the reactive ultraviolet absorber has a hydroxyl group, an amino group, a carboxyl group, an epoxy group, an isocyanate group, or the like as a reactive functional group, a heat having a functional group reactive with the reactive functional group. A reactive ultraviolet absorber can be reactively fixed to the thermoplastic resin by heat or the like using a plastic resin and, if necessary, a catalyst.

In the present invention, the reactive ultraviolet absorber is copolymerized with a resin component such as a monomer, an oligomer, or a reactive polymer to obtain an ultraviolet-absorbing copolymer, which is then used as the thermal transfer resin. It is added in the layer or laminated as a layer to constitute the heat transferable resin layer.
Examples of the monomer component to be copolymerized with the reactive ultraviolet absorber include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and tertiary butyl. (Meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, lauryl tridecyl (meth) acrylate, tridecyl (meth) acrylate, seryl stearyl (meth) acrylate, stearyl (meth) acrylate, ethylhexyl (meth) acrylate, Octyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, (meth) acrylic acid, hydroxyethyl (meth) acrylate, hydroxypropyl ( (Meth) acrylates such as acrylate), dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, tertiary butylaminoethyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate; (Meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, decaethylene glycol di (meth) acrylate, pentadecaethylene glycol di (meth) acrylate, pentacon Tahecta ethylene glycol di (meth) acrylate, butylene di (meth) acrylate, allyl (meth) acrylate, trimethylolpropane Li (meth) acrylate, hexanediol di (meth) acrylate, tripropylene glycol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) Bifunctional or higher (meth) acrylates such as acrylate, neopentyl glycol penta (meth) acrylate, phosphazene hexa (meth) acrylate, and the like can be given. In the present specification, (meth) acrylate means acrylate or methacrylate.

Further, the resin component for reactively bonding the reactive ultraviolet absorber may be used not only as the monomer component but also as an oligomer, and further from a polymer (reactive polymer) of the monomer component or a derivative thereof. Polyester (meth) acrylate-based, epoxy (meth) acrylate-based, urethane (meth) acrylate-based, and polyether (meth) acrylate-based (meth) acrylic reactive polymers can also be used. These monomers, oligomers, and (meth) acrylic reactive polymers may be used alone or in combination of two or more.

By copolymerizing the above-mentioned monomer, oligomer, or (meth) acrylic reactive polymer and a reactive ultraviolet absorber, a copolymer obtained by reactively bonding the reactive ultraviolet absorber can be obtained. As a reactive ultraviolet absorber amount contained in a copolymer, the range of 10-90 mass% is preferable. If it is less than 10% by mass, it is difficult to obtain satisfactory light resistance. On the other hand, if it exceeds 90% by mass, problems such as stickiness at the time of coating and image bleeding at the time of transfer to a dye image are not preferred. A more preferable lower limit is 30% by mass, and a more preferable upper limit is about 70% by mass.
Further, the molecular weight of the copolymer obtained by reactively bonding the reactive ultraviolet absorber is preferably about 5000 to 250,000 in terms of mass average molecular weight. When the molecular weight is less than 5,000, the coating film is weak and the durability as a heat transferable resin layer may not be sufficiently obtained. On the other hand, if it exceeds 250,000, when the heat transferable resin layer is transferred with a thermal head or the like, the film breakage or the like deteriorates, which is not preferable. A more preferred lower limit is 9000, and a more preferred upper limit is about 30,000.
In addition, the said mass mean molecular weight is the value measured by polystyrene conversion by GPC method.

Further, in the protective layer transfer sheet of the present invention, when the thermal transfer resin layer contains a resin component other than the copolymer to which the reactive ultraviolet absorber is reactively bonded, the reactive ultraviolet absorber is reactively bonded. The content of the copolymer is preferably 5 parts by mass or more with respect to 100 parts by mass of the solid content of the protective layer. If the amount is less than 5 parts by mass, a protective layer having sufficient light resistance may not be formed on the image of the printed matter. A more preferred lower limit is 10 parts by mass.

The thermal transfer resin layer can be used in combination with other ultraviolet absorbers. Examples of other ultraviolet absorbers that can be used in combination include benzotriazole, benzophenone, salicylate, and hindered amine. Moreover, you may use the copolymer resin which reacted-bonded these ultraviolet absorbers and the resin component mentioned above.
Although it does not specifically limit as such an ultraviolet absorber, Specifically, the ultraviolet absorber etc. which have the unsaturated double bond described in Unexamined-Japanese-Patent No. 2003-54142 are mentioned, for example.

Further, the thermal transfer resin layer has various additives such as an organic filler, an inorganic filler, an ultraviolet absorber, an antioxidant, and a fluorescent brightening agent in order to further improve the scratch resistance, chemical resistance, weather resistance and the like. May be contained. Further, the thermal transfer resin layer may further contain a conventionally known resin component in addition to the above-described copolymer.

The heat transferable resin layer containing the copolymer or the like obtained by reactively bonding the above-described reactive ultraviolet absorber is transferred to the printing screen of the transfer target by thermal transfer. Accordingly, the functions that the thermal transfer resin layer should have include that the thermal transfer is surely peeled off from the base film or the release layer provided on the base film with good film cutting properties, and the thermal adhesiveness to the transfer object. As a protective layer of the printing screen, various resistances such as friction resistance and scratch resistance, particularly excellent light resistance can be imparted in the present invention, and transparency is good and the image clarity on the transfer surface is not impaired. And so on. From this point, the thermal transfer resin layer can be provided as a single layer like the thermal transfer resin layer 12 shown in FIG. 1, but as in the thermal transfer resin layer 22, 32 or 42 shown in FIGS. In the order of the transparent resin layer and the heat-adhesive resin layer from the base film side, or in the order of the transparent resin layer, the ultraviolet blocking layer and the heat-adhesive resin layer, it is provided in a multilayer structure of two or three layers. It is also preferable. Each layer in such a case will be described below.

(Transparent resin layer)
The transparent resin layer provided on the base film or release layer, that is, the base film side layer of the thermal transfer resin layer, should be made of a resin excellent in friction resistance, transparency, hardness, etc. preferable.
Specifically, for example, polyester, polystyrene, acrylic resin, polyurethane, acrylic urethane resin and silicone-modified resins of these resins, and mixtures of these resins, as well as polymerizable monomers, oligomers, reactive heavy resins as described above. A resin obtained by crosslinking and curing at least one kind of coalescence or the like by ionizing radiation irradiation can be used.
Moreover, in order to improve flexibility and adhesiveness, the above-mentioned resin may be used by mixing a thermoplastic resin having good compatibility.

In the case of crosslinking and curing by ionizing radiation, an intermediate layer (primer layer) made of acrylic resin, urethane resin, polyester, polystyrene, acrylic urethane resin or the like is used in order to further improve the adhesion to the ultraviolet blocking layer described later. ) May be provided.

These resins are excellent in transparency but tend to form a relatively tough film, so that the film is not sufficiently cut off during transfer. Therefore, highly transparent fine particles such as silica, alumina, calcium carbonate, and plastic pigments are used to improve the film breakability of these transparent resins and the friction and scratch resistance of the printing screen coated by transfer. Or wax can be added to such an extent that the transparency of the resin is not impaired. The addition amount is preferably 0.5 to 20 parts by weight with respect to 100 parts by weight of the resin solid content. Moreover, in order to further improve friction resistance and scratch resistance, additives such as silicone-modified resins and lubricants may be contained.

As a method for forming such a transparent resin layer, gravure coating, gravure reverse coating, roll coating, and many other means can be used. Specifically, it can be formed by applying and drying a coating solution containing the above resin.
The thickness of the transparent resin layer is preferably about 0.1 to 50 μm as a dry film, more preferably a lower limit of 1 μm, and a more preferable upper limit of about 10 μm.

(UV blocking layer)
In the present invention, the resin to which the reactive ultraviolet absorbent is reactively bonded may be contained in the transparent resin layer and / or the heat-adhesive resin layer when the thermal transfer resin layer is composed of multiple layers. A separate barrier layer may be provided. In this case, it is not limited whether it is provided between the transparent resin layer and the heat-adhesive resin layer or between the base film or the release layer and the transparent resin layer. It is preferable to provide between the functional resin layers.
The method for forming the ultraviolet blocking layer may be the same as the method for forming the transparent resin layer, and the thickness is preferably about 0.1 to 5 μm, for example.

(Thermal adhesive resin layer)
The thermal adhesive resin layer is provided on the uppermost layer of the thermal transferable resin layer in order to transfer each of the above layers onto the printing screen with good adhesiveness. For example, acrylic resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer resin, styrene-acryl copolymer resin, polyester resin, polyamide resin, etc. Such a resin having good adhesiveness when heated can be used.
One or two or more of these resins in a form that can be applied as a solution or an emulsion is selected from the application methods listed for the transparent resin layer, and then applied and dried. Can be formed.
As thickness of the said thermoadhesive resin layer, the range of about 0.1-5 micrometers is preferable, for example.

(Back layer)
In the protective layer transfer film of the present invention, the opposite surface of the substrate film provided with the heat transferable resin layer is adhered to a thermal head, a transfer hot plate, etc. A back layer (heat resistant slip layer) can be provided for the purpose of preventing and improving slipperiness (see FIG. 4). As the material for the back layer, for example, a conventionally known material such as a resin obtained by curing a butyral resin or the like with an isocyanate compound or a silicone resin can be used as it is.
As thickness of the said back surface layer, about 0.1-5 micrometers is preferable, for example.
Moreover, the said back surface layer may be provided through the primer layer as needed.

The above-described single-layer or multi-layered thermal transfer resin layer preferably has an overall thickness of about 0.5 to 50 μm.
The thermal transfer resin layer may be provided alone on the base film to form a transfer film having only the thermal transfer resin layer. However, the protective layer transfer sheet of the present invention further includes yellow (Y), magenta (M ), Cyan (C) and / or black (Bk) dye layers, or yellow (Y), magenta (M), cyan (C) and / or black (Bk) hot-melt inks The layer may have a structure in which the layers are formed in the surface order on the base film.
The dye layer is composed of a suitable sublimable dye and a suitable binder resin by a known method, and the heat-meltable ink layer is composed of a suitable pigment and a heat-meltable substance such as a suitable wax by a known method. Formed from.

When the thermal transfer resin layer and the dye layer, etc. have a structure formed in the surface sequence on the base film, the plate pattern is not particularly limited. For example, the following layer pattern is repeated in the surface sequence. The protective layer transfer sheet provided is mentioned. In the following description, Ye, Mg, and Cy are dye layers, and Bk indicates a dye layer or a hot-melt ink layer.

(1) Ye dye layer, Mg dye layer, Cy dye layer, thermal transfer resin layer (2) Ye dye layer, Mg dye layer, Cy dye layer, Bk dye layer, thermal transfer resin layer (3) Ye dye layer, Mg Dye layer, Cy dye layer, Bk melt ink layer, thermal transfer resin layer (4) Bk dye layer, thermal transfer resin layer (5) Bk melt ink layer, thermal transfer resin layer

In these plate patterns, the Bk dye layer, the Bk melted ink layer, and the thermal transfer resin layer may be formed larger in size than other layers. The detection mark for detecting each layer may be provided anywhere on each layer, for example, at the head of each layer region or the head of the top color.
In the protective layer transfer sheet having a structure in which the ink layer and the heat transferable resin layer as described above are formed in the surface order on the base film, each layer constituting the heat transferable resin layer is a transparent resin layer. Since it is necessary to print these with a predetermined pattern in alignment, these layers are added with an additive such as a fluorescent brightening agent, and are visually or mechanically detected by ultraviolet irradiation or the like. Matching can be facilitated.
In addition, regarding the thermal transfer ink layer described above, the ink and the method used for the conventionally known thermal transfer (ink) film can be used as they are for the material of the ink to be used and the method of providing it on the substrate film surface.

The image to be protected using the protective layer transfer sheet as described above is usually an image formed by a sublimation type thermal transfer method and / or a melt type thermal transfer method, but is not limited to this and can be widely used. It is. In particular, when applied to an image by sublimation thermal transfer, a protective layer is formed on the image, and the dye forming the image is re-colored by heat at the time of transfer, so the image becomes clearer. There is an effect of becoming.

Thus, the printed matter formed by transferring the thermal transfer resin layer onto the printed screen of the printed matter using the protective layer transfer sheet of the invention is also one aspect of the present invention.
That is, in the printed matter of the present invention, the above-described thermal transfer resin layer of the protective layer transfer sheet of the present invention is laminated on at least a part of a printing screen having an image colored with at least a dye.

Sublimation type thermal transfer images and / or melt type thermal transfer images can be any of image receiving sheets and card base materials such as polyester resins, vinyl chloride resins, vinyl chloride-vinyl acetate copolymer resins, and polycarbonate plastic sheets. It may be formed on such a transfer material. For example, a thermal transfer image receiving sheet provided with a dye-accepting resin layer (receiving layer) on a base sheet, or a film, sheet, molded product or the like made of these resins can be used.
The card base may be pre-formed with the necessary magnetic recording layer, embossed pattern, other printed pattern, optical memory, IC memory, bar code, etc. on the surface, or sublimation transfer. These magnetic recording layers and the like may be provided after information such as a facial photograph is formed by a method or the like. The face photograph provided on the card substrate can be formed according to a conventional method using a sublimation thermal transfer sheet. At the same time, information such as characters and barcodes can be formed on a sublimation type thermal transfer sheet, but it is preferable to form such information using a hot melt ink type thermal transfer sheet capable of high density black printing.
Examples of the dye-accepting resin include polyolefin resins such as polypropylene, halogenated resins such as polyvinyl chloride and polyvinylidene chloride, vinyl resins such as polyvinyl acetate and various polyacrylates, polyethylene terephthalate, polybutylene terephthalate, and the like. Polyester resins, polystyrene resins such as polystyrene or copolymers thereof, polyamide resins, copolymers of olefins such as ethylene and propylene and other vinyl monomers, and ionomers, cellulose diacetate, cellulose triacetate, etc. In order to prevent fusion with the thermal transfer sheet, a release agent such as silicone oil may be added to these resin layers.

The sheet-like base material used for the thermal transfer image-receiving sheet includes (1) synthetic paper (polyolefin, polystyrene, etc.), (2) fine paper, art paper, coated paper, cast coated paper, wallpaper, backing paper, synthetic paper Resin solution or emulsion impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internal paper, paperboard, other natural fiber paper such as cellulose fiber paper, (3) polyolefin, polyvinyl chloride, polyethylene terephthalate, polystyrene, polymethyl methacrylate, polycarbonate Various plastic films or sheets such as can be used. Among them, the synthetic paper (1) preferably has a microvoid layer having a low thermal conductivity (in other words, a high heat insulating property) on its surface. Moreover, the laminated body by the arbitrary combinations of said (1)-(3) can also be used.
Examples of typical laminates include cellulose fiber paper and synthetic paper, or a laminate of cellulose fiber paper and a plastic film or sheet.

As described above, a color image and / or a character image is formed on an image receiving sheet or a card by a thermal printer, and the thermal transfer resin layer is transferred thereon using the protective layer transfer sheet of the present invention. A protective layer is formed on the thermal printer.For transfer, the thermal printer may set transfer conditions separately for sublimation transfer, melt transfer, and protective layer transfer. The printing energy may be adjusted appropriately. In the protective layer transfer sheet of the present invention, the heating means is not limited to the thermal printer, and other heating plates, hot stampers, hot rolls, line heaters, irons and the like can also be used for transfer. Further, the thermal transfer resin layer may be transferred to the entire surface of the formed image or may be transferred only to a specific portion. Furthermore, although it cannot be said that it is a transfer film, it can also be applied as a pouch material made of a laminate sheet used in, for example, a restaurant menu or cards. In this case, on one surface of a transparent substrate film or a commercially available laminate sheet, the ultraviolet blocking layer and the heat-adhesive resin layer in the present invention are provided to form a laminate sheet, which is a sublimation type thermal transfer method and / or a melt type. It is also possible to use heat bonding on an image formed by a thermal transfer method.

Since the protective layer transfer sheet of the present invention uses a resin in which a reactive ultraviolet absorber is reactively bonded in the thermal transfer resin layer, it is compared with a conventional ultraviolet absorber contained in the thermal transfer resin layer. Thus, the vaporization, divergence and decomposition of the ultraviolet absorber due to heat, or elution by the solvent is reduced. Therefore, the protective layer obtained by transferring the thermal transfer resin layer onto the thermal transfer image by the protective layer transfer sheet of the present invention is excellent in various resistances such as friction resistance, scratch resistance, pharmaceutical resistance, and storage resistance, and in particular. Therefore, it is excellent in light resistance, and a printed matter having these properties can be provided.

Next, an Example and a comparative example are given and this invention is further explained in full detail. In the text, “part” or “%” is based on mass unless otherwise specified.

(Sublimation type thermal transfer film)
A special thermal transfer sheet for MegaPixel III manufactured by Altec ADS was used as a sublimation type thermal transfer film having ink layers of sublimable dyes of three colors of yellow, magenta and cyan.

(Thermal transfer image receiving sheet)
As the thermal transfer image receiving sheet, a dedicated thermal transfer image receiving sheet for MegaPixel III manufactured by Altec ADS was used.

Example 1
Gravure coating method with a 5μm thick PET film (trade name Lumirror manufactured by Toray Industries, Inc.) as a base film and a heat-resistant slip layer made of silicone resin as a back layer on one side so that the thickness when dried is 1μm The transparent resin layer coating liquid having the following composition is applied to the other surface by a gravure coating method so that the coating amount when dried is 3 g / m ² and dried to form a transparent resin layer. did.

(Composition of coating solution for transparent resin layer)
Acrylic resin (Dianar BR-83, manufactured by Mitsubishi Rayon Co., Ltd.) 20 parts Methyl ethyl ketone / toluene (weight ratio 1: 1) 80 parts

Next, on the formed transparent resin layer, a thermal adhesive resin layer coating solution having the following composition is applied by a gravure coating method so that the coating amount upon drying is 1 g / m ² , dried and heated. An adhesive resin layer was formed, and a protective layer transfer sheet of Example 1 provided with a thermal transfer resin layer composed of a transparent resin layer and a thermal adhesive resin layer was produced.

(Composition of coating solution for thermal adhesive resin layer)
Copolymer resin (2,4-diphenyl-6- [2-hydroxy-4- (2-acryloyloxyethoxy)]-s-triazine 30 mol% and methyl methacrylate 70 mol% reactively bonded with a reactive ultraviolet absorber Copolymer) 20 parts methyl ethyl ketone / toluene (weight ratio 1: 1) 80 parts

(Example 2)
A protective layer transfer sheet was produced in the same manner as in Example 1 except that the composition of the coating solution for the heat-adhesive resin layer was changed to the following.
(Composition of coating solution for thermal adhesive resin layer)
Polyester resin (Byron 700, manufactured by Toyobo Co., Ltd.) 20 parts UV absorber (Tinuvin 900, manufactured by Ciba Japan Co., Ltd.) 3 parts Copolymer resin (2,4-diphenyl-6- [2] reactively bonded with a triazine-based reactive UV absorber -Hydroxy-4- (2-acryloyloxyethoxy)]-s-triazine 30 mol% and methyl methacrylate 70 mol% copolymer) 7 parts methyl ethyl ketone / toluene (weight ratio 1: 1) 70 parts

(Comparative Example 1)
A protective layer transfer sheet was produced in the same manner as in Example 1 except that the composition of the coating solution for the heat-adhesive resin layer was changed to the following.
(Composition of coating solution for thermal adhesive resin layer)
Copolymer resin conjugated with benzotriazole-based reactive UV absorber (PUVA-30M, Otsuka Chemical Co., Ltd.) 20 parts Methyl ethyl ketone / toluene (weight ratio 1: 1) 80 parts

(Evaluation)
The following evaluation was performed using the protective layer transfer sheets prepared in Examples and Comparative Examples.

(Hue change)
First, on the dye-coated surface of the previously produced sublimation type thermal transfer film, the electrical signal obtained by superimposing the previously produced thermal transfer image-receiving sheet and color-separating the image from the printer (manufactured by Altec ADS, for MegaPixel III) Thermal energy was applied through a thermal head to form a gradation image.

Next, using the protective layer transfer sheets prepared in Examples and Comparative Examples, the respective thermal transfer resin layers were transferred with the thermal head of the same printer to form a gradation image with a protective layer.

Using the thermal transfer image-receiving sheet transferred with the gradation image and the protective layer obtained as described above, the light resistance of the image surface was irradiated with 400 KJ / m ² with a xenon weatherometer (Ci4000 manufactured by Atlas Co.), and the hue before and after irradiation. Was measured with a spectrophotometer (Spectaglino, manufactured by GretagMacbeth), and the chromaticity difference Δa ^* b ^* (hue change) before and after the test was calculated according to the following formula.
Chromaticity difference Δa ^* b ^*
= {(A value after irradiation−a value before irradiation) ² + (b value after irradiation−b value before irradiation) ² } ^1/2
As a result, it was confirmed that the sample to which the protective layer transfer sheet according to the example was transferred had less hue change of yellow and magenta than the transfer sample of the protective layer transfer sheet according to the comparative example. FIG. 5 shows the yellow hue change of Examples 1 and 2 and Comparative Example 1, and FIG. 6 shows the magenta hue change of Examples 1, 2 and Comparative Example 1. Table 1 shows the value of Δa ^* b ^{* in} the vicinity of the optical density of 1.0 for the samples according to Examples 1 and 2 and Comparative Example 1.

It is sectional drawing which shows typically an example of the protective layer transfer sheet of this invention. It is sectional drawing which shows typically another example of the protective layer transfer sheet of this invention. It is sectional drawing which shows typically another example of the protective layer transfer sheet of this invention. It is sectional drawing which shows typically another example of the protective layer transfer sheet of this invention. 6 is a graph showing a yellow hue change result of a printed material to which a protective layer transfer sheet according to Example 1 and Comparative Example 1 is transferred. 6 is a graph showing a magenta hue change result of a printed material to which a protective layer transfer sheet according to Example 1 is transferred. It is a graph which shows the light absorbency of the copolymer which the benzophenone, the benzotriazole, or the triazine type compound reacted-bonded.

Explanation of symbols

10, 20, 30, 40 Protective layer transfer sheet 11, 21, 31, 41 Base film 12, 22, 32, 42 Thermal transfer resin layers 23, 33, 43 Transparent resin layers 24, 34, 44 Thermal adhesive resin Layers 35 and 45 UV blocking layer 46 Release layer 47 Back layer

Claims (4)

A protective layer transfer sheet having a base film and a heat transferable resin layer, and transferring the heat transferable resin layer by thermal transfer onto an image printed on a transfer target;
The protective layer transfer sheet, wherein the thermal transfer resin layer contains a copolymer in which a triazine compound having a reactive functional group is reactively bonded. The protective layer transfer sheet according to claim 1, wherein the triazine-based compound having a reactive functional group has a structure represented by the following general formula (1).

In General Formula (1), R ¹ represents an alkylene group having 1 to 6 carbon atoms, R ² represents a hydrogen atom or a methyl group, and R ³ represents an alkyl group or alkoxy group having 1 to 6 carbon atoms, or Represents a hydrogen atom. Further, yellow (Y), magenta (M), cyan (C) and / or black (Bk) dye layers, or yellow (Y), magenta (M), cyan (C) and / or black ( The protective layer transfer sheet according to claim 1 or 2, wherein the heat-meltable ink layer of each color of Bk) is formed in the surface order on the base film. A printed material, wherein the thermal transfer resin layer of the protective layer transfer sheet according to claim 1, 2 or 3 is laminated on at least a part of a printing screen having an image colored with at least a dye.

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